保持我的问题总之，我已经创建了一个应用程序有3个活动，其中A - 类名单，B - 产品清单，C - 单个项目。在B和C的数据显示，从网上XML解析。但是，如果我去到A - > B1 - > C，然后再返回到A，然后回到B1，我想有它的数据缓存的地方，所以我就不必再次请求XML

keeping my question short, I have created an application with 3 activities, where A - list of categories, B - list of items, C - single item. Data displayed in B and C is parsed from online XML. But, if I go through A -> B1 -> C, then back to A and then back to B1, I would like to have its data cached somewhere so I wouldn't have to request the XML again.

我是新来的Andr​​oid和Java编程，我GOOGLE了很多，但仍无法找到（或根本就没有一个想法去哪里找）的方式做我想做的。

I'm new to Android and Java programming, I've googled a lot and still can't find (or simply do not have an idea where to look) a way to do what I want.

会存储所有收到的主要活动数据（包含HashMap？ContentProviders？），然后传递给B和C（如果他们那是以前同样的要求）是一个好主意？

Would storing all received data in main activity A (HashMaps? ContentProviders?) and then passing to B and C (if they get same request that was before) be a good idea?

推荐答案

一个简单快速的方法来缓存信息，或者跟踪应用程序的状态，就是在描述延长的应用程序的< A HREF =htt​​p://blog.tomgibara.com/post/126377651/global-application-state-in-android>这篇博客。

A simple and fast way to cache information or to keep track of the application state, is to extend the Application as described in this blog post.

本博客文章忘记补充一点，你必须设置你的 CustomApplication 的清单中类，如：

This blog post forgets to add that you have to set your CustomApplication class in the manifest, like:

<application [...] android:name="CustomApplication">

在我的项目中，我首先通过getInstance坚持单身风格。

In my projects I stick to the singleton style via getInstance.

更多资源：这个答案，的